Shorter, rough trunnion surfaces are associated with higher taper wear rates than longer, smooth trunnion surfaces in a contemporary large head metal-on-metal total hip arthroplasty system.

Autor: Brock TM; Newcastle University, Newcastle, United Kingdom., Sidaginamale R; Newcastle University, Newcastle, United Kingdom., Rushton S; Newcastle University, Newcastle, United Kingdom., Nargol AV; Department of Orthopaedics, University Hospital of North Tees, North Tees, United Kingdom., Bowsher JG; FDA, Silver Spring, Maryland., Savisaar C; FDA, Silver Spring, Maryland., Joyce TJ; Newcastle University, Newcastle, United Kingdom., Deehan DJ; Newcastle University, Newcastle, United Kingdom., Lord JK; Biomedical and General Engineering, California Polytechnic State University, San Luis Obispo, California., Langton DJ; North Tees Explant Centre (NTEC), University Hospital of North Tees, North Tees, United Kingdom.
Jazyk: angličtina
Zdroj: Journal of orthopaedic research : official publication of the Orthopaedic Research Society [J Orthop Res] 2015 Dec; Vol. 33 (12), pp. 1868-74. Date of Electronic Publication: 2015 Jul 25.
DOI: 10.1002/jor.22970
Abstrakt: Taper wear at the head-neck junction is a possible cause of early failure in large head metal-on-metal (LH-MoM) hip replacements. We hypothesized that: (i) taper wear may be more pronounced in certain product designs; and (ii) an increased abductor moment arm may be protective. The tapers of 104 explanted LH-MoM hip replacements revised for adverse reaction to metal debris (ARMD) from a single manufacturer were analyzed for linear and volumetric wear using a co-ordinate measuring machine. The mated stem was a shorter 12/14, threaded trunnion (n=72) or a longer, smooth 11/13 trunnion (n=32). The abductor moment arm was calculated from pre-revision radiographs. Independent predictors of linear and volumetric wear included taper angle, stem type, and the horizontal moment arm. Tapers mated with the threaded 12/14 trunnion had significantly higher rates of volumetric wear (0.402 mm3/yr vs. 0.123 mm3/yr [t=-2.145, p=0.035]). There was a trend to larger abductor moment arms being protective (p=0.055). Design variation appears to play an important role in taper-trunnion junction failure. We recommend that surgeons bear these findings in mind when considering the use of a short, threaded trunnion with a cobalt-chromium head.
(© 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)
Databáze: MEDLINE
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